Some studies show that caffeine can modestly increase how fast blood thinners like aspirin are absorbed and how much is available to the body, making the bleeding side effect more pronounced.

Aspirin has been around for a long time and ... with ibuprofen or codeine if necessary and often comes in capsules with caffeine. Caffeine, it was recently discovered, can enhance the effects ...

Aspirin 650mg, caffeine 33.3mg, salicylamide 195mg; per powder; contains potassium 55mg/powder. Place powder on tongue and follow with liquid; or may stir into glass of water or other liquids.